Bulk magnetic properties of distorted square lattice compounds M'-LnTaO4 (Ln = Tb, Dy, Ho, Er)

Abstract

We report bulk magnetic properties of the monoclinic lanthanide tantalates, M'-LnTaO4 (Ln = Tb, Dy, Ho, Er), where the magnetic Ln3+ ions are arranged on a distorted 2D square lattice. The heavier analogue M'-YbTaO4 has been investigated as a spin-orbit-coupled, quasi-two-dimensional frustrated magnet, and the properties of the other M'-LnTaO4 are expected to vary depending on the electronic configuration of the Ln ion, namely Kramers vs non-Kramers behaviour and different crystal electric field parameters. In this work, powder neutron diffraction is used to confirm the crystal structure for Ln = Tb, Ho, Er, and to determine the magnetic structure of M'-TbTaO4, which displays long-range antiferromagnetic (AFM) order below T_N = 2.1 K. The Tb3+ moments are aligned primarily along the c-axis with AFM nearest-neighbour interactions. Susceptibility data suggest that M'-DyTaO4 may display short-range ordering around 2.7 K, while M'-HoTaO4 and M'-ErTaO4 show AFM correlations but do not order above 1.8 K. Measurements of the magnetic specific heat provide evidence for a Kramers doublet ground state in M'-ErTaO4, similar to its heavier analogue M'-YbTaO4.

37 pages including Supplemental Material (as appendices)

References in corpus (8)

• Tutorial: A Beginner's Guide to Interpreting Magnetic Susceptibility Data with the Curie-Weiss Law
• Magnetic properties of monoclinic lanthanide orthoborates, $Ln$BO${}_3$, $Ln$ = Gd, Tb, Dy, Ho, Er, Yb
• Sensitivity of magnetic properties to chemical pressure in lanthanide garnets $L{n}_3{A}_2{X}_3{\text{O}}_{12}$, $Ln$ = Gd, Tb, Dy, Ho, $A$ = Ga, Sc, In, Te, $X$ = Ga, Al, Li
• Magnetism on the stretched diamond lattice in lanthanide orthotantalates
• Quantum magnetism in the frustrated square lattice oxyhalides YbBi2IO4 and YbBi2ClO4
• Contrasting Magnetic Structures in SrLaCuSbO${}_6$ and SrLaCuNbO${}_6$: Spin-1/2 Quasi-Square-Lattice $J_1-J_2$ Heisenberg Antiferromagnets
• Magnetoelastic coupling in the stretched diamond lattice of TbTaO${}_4$
• High-pressure synthesis of quantum magnet M-YbTaO4 with a stretched diamond lattice